/* ==========================================================================
   Grammar Intelligence Lab — assets/grammar-formula-lab.css
   Scoped under .gl-*. Reuses site tokens from style.css / home.css and the
   .mv-shelf / .mv-feature-card card system (same family as Math Tools /
   PDF Tools) so the page matches the rest of MulVidya.
   ========================================================================== */

.vt-shell{ max-width: 1180px; margin: 0 auto; padding: 0 20px 60px; }

/* ---------------------------------------------------------------------- */
/* HERO                                                                    */
/* ---------------------------------------------------------------------- */
.gl-hero{
  position: relative; max-width: 780px; margin: 6px auto 10px;
  text-align: center; padding: 18px 16px 4px;
}
.gl-hero-symbols{ position:absolute; inset:-30px -10px auto -10px; height:200px; pointer-events:none; z-index:0; overflow:hidden; }
.gl-symbol{ position:absolute; font-family: var(--font-display); font-weight:800; color: var(--accent); opacity:.14; animation: gl-float 7s ease-in-out infinite; }
.gl-symbol:nth-child(1){ left:4%; top:14%; font-size:34px; animation-delay:.1s; }
.gl-symbol:nth-child(2){ left:16%; top:58%; font-size:22px; animation-delay:1.1s; color:var(--accent-2); }
.gl-symbol:nth-child(3){ left:82%; top:10%; font-size:30px; animation-delay:.5s; color:var(--accent-3); }
.gl-symbol:nth-child(4){ left:90%; top:56%; font-size:20px; animation-delay:1.6s; }
.gl-symbol:nth-child(5){ left:48%; top:6%; font-size:18px; animation-delay:2.1s; color:var(--accent-2); }
.gl-symbol:nth-child(6){ left:60%; top:64%; font-size:26px; animation-delay:.8s; color:var(--accent-3); }
@keyframes gl-float{ 0%,100%{ transform:translateY(0);} 50%{ transform:translateY(-10px);} }

.gl-eyebrow{ position:relative; z-index:1; display:inline-block; font-family:var(--font-body); font-weight:600; font-size:13px; color:var(--accent); background:rgba(110,91,214,.1); border:1px solid rgba(110,91,214,.25); padding:5px 14px; border-radius:99px; margin-bottom:12px; }
.gl-hero h1{ position:relative; z-index:1; font-family:var(--font-display); font-size:38px; margin:0 0 10px; }
.gl-hero p{ position:relative; z-index:1; color:var(--ink-soft); font-size:15.5px; line-height:1.6; max-width:640px; margin:0 auto; }
.gl-hero-badges{ position:relative; z-index:1; display:flex; flex-wrap:wrap; gap:8px; justify-content:center; margin-top:16px; }
.gl-badge{ font-size:12.5px; font-weight:600; color:var(--ink-soft); background:var(--surface-2); border:1px solid var(--border); padding:5px 12px; border-radius:99px; }

/* ---------------------------------------------------------------------- */
/* SMART SEARCH                                                            */
/* ---------------------------------------------------------------------- */
.gl-search-wrap{ max-width:620px; margin:18px auto 6px; position:relative; z-index:5; }
.gl-search{ display:flex; align-items:center; gap:10px; background:var(--surface); border:1.5px solid var(--border); border-radius:var(--radius-lg); padding:12px 18px; box-shadow:var(--shadow-sm); transition:border-color .15s, box-shadow .15s; }
.gl-search:focus-within{ border-color:var(--accent); box-shadow:0 0 0 4px rgba(110,91,214,.12); }
.gl-search svg{ width:19px; height:19px; stroke:var(--ink-faint); fill:none; stroke-width:2; flex-shrink:0; }
.gl-search input{ flex:1; border:none; outline:none; background:transparent; font-family:var(--font-body); font-size:15px; color:var(--ink); }
.gl-search input::placeholder{ color:var(--ink-faint); }
.gl-search-clear{ border:none; background:var(--surface-2); color:var(--ink-faint); width:22px; height:22px; border-radius:50%; cursor:pointer; font-size:13px; line-height:1; display:none; }
.gl-search-clear.show{ display:block; }
.gl-search-results{ position:absolute; top:calc(100% + 8px); left:0; right:0; background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-md); box-shadow:var(--shadow-lg); max-height:340px; overflow:auto; display:none; z-index:20; }
.gl-search-results.show{ display:block; }
.gl-search-hit{ display:flex; align-items:center; gap:10px; padding:11px 16px; cursor:pointer; border-bottom:1px solid var(--border); }
.gl-search-hit:last-child{ border-bottom:none; }
.gl-search-hit:hover, .gl-search-hit.active{ background:var(--surface-2); }
.gl-search-hit strong{ font-size:14px; }
.gl-search-hit span{ font-size:12.5px; color:var(--ink-faint); }
.gl-search-empty{ padding:16px; text-align:center; color:var(--ink-faint); font-size:13.5px; }

/* ---------------------------------------------------------------------- */
/* MODE TABS                                                               */
/* ---------------------------------------------------------------------- */
.gl-modes{ display:flex; flex-wrap:wrap; gap:8px; justify-content:center; margin:22px 0 8px; }
.gl-mode-btn{ font-family:var(--font-body); font-weight:600; font-size:13.5px; color:var(--ink-soft); background:var(--surface); border:1.5px solid var(--border); padding:9px 16px; border-radius:99px; cursor:pointer; transition:all .15s; display:flex; align-items:center; gap:7px; }
.gl-mode-btn svg{ width:16px; height:16px; stroke:currentColor; fill:none; stroke-width:2; }
.gl-mode-btn:hover{ border-color:var(--accent); color:var(--accent); }
.gl-mode-btn.is-active{ background:var(--accent); color:var(--accent-ink); border-color:var(--accent); }

.gl-view{ display:none; padding-top:10px; }
.gl-view.is-active{ display:block; }

/* ---------------------------------------------------------------------- */
/* CATEGORY BAR + TOPIC GRID                                               */
/* ---------------------------------------------------------------------- */
.gl-catbar{ display:flex; flex-wrap:wrap; gap:8px; justify-content:center; margin:14px 0 20px; }
.gl-cat-btn{ font-family:var(--font-body); font-size:13px; font-weight:600; color:var(--ink-soft); background:var(--surface-2); border:1px solid var(--border); padding:7px 14px; border-radius:99px; cursor:pointer; }
.gl-cat-btn.is-active{ background:var(--accent); color:var(--accent-ink); border-color:var(--accent); }

.gl-grid{ display:grid; grid-template-columns:repeat(auto-fill, minmax(230px,1fr)); gap:14px; }
.gl-topic-card{ text-align:left; cursor:pointer; background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-md); padding:16px; box-shadow:var(--shadow-sm); transition:transform .15s, box-shadow .15s, border-color .15s; display:flex; flex-direction:column; gap:8px; }
.gl-topic-card:hover{ transform:translateY(-3px); box-shadow:var(--shadow-md); border-color:var(--accent); }
.gl-topic-icon{ width:36px; height:36px; border-radius:10px; background:rgba(110,91,214,.12); color:var(--accent); display:flex; align-items:center; justify-content:center; font-size:17px; }
.gl-topic-card h4{ font-family:var(--font-display); font-size:15.5px; margin:0; }
.gl-topic-card p{ font-size:12.8px; color:var(--ink-soft); margin:0; line-height:1.45; flex:1; }
.gl-topic-formula-preview{ font-family:'Courier New',monospace; font-size:11.3px; color:var(--accent); background:var(--surface-2); padding:6px 8px; border-radius:8px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.gl-topic-go{ font-size:12px; font-weight:700; color:var(--accent); display:flex; align-items:center; gap:4px; }
.gl-topic-go svg{ width:13px; height:13px; stroke:currentColor; fill:none; stroke-width:2.4; }

/* ---------------------------------------------------------------------- */
/* MODAL — topic detail                                                    */
/* ---------------------------------------------------------------------- */
.gl-overlay{ position:fixed; inset:0; background:rgba(10,10,18,.55); backdrop-filter:blur(3px); display:none; align-items:flex-start; justify-content:center; z-index:200; padding:26px 14px; overflow:auto; }
.gl-overlay.show{ display:flex; }
.gl-modal{ background:var(--surface); border-radius:var(--radius-lg); max-width:820px; width:100%; box-shadow:var(--shadow-lg); position:relative; margin-bottom:40px; }
.gl-modal-close{ position:absolute; top:14px; right:14px; width:32px; height:32px; border-radius:50%; background:var(--surface-2); border:1px solid var(--border); color:var(--ink-soft); cursor:pointer; font-size:16px; z-index:2; }
.gl-modal-head{ padding:24px 26px 14px; border-bottom:1px solid var(--border); }
.gl-modal-head .gl-cat-chip{ font-size:11.5px; font-weight:700; color:var(--accent); background:rgba(110,91,214,.1); padding:3px 10px; border-radius:99px; display:inline-block; margin-bottom:8px; }
.gl-modal-head h2{ font-family:var(--font-display); font-size:24px; margin:0 0 6px; }
.gl-modal-head p{ color:var(--ink-soft); font-size:14px; margin:0; }
.gl-modal-body{ padding:20px 26px 26px; }

.gl-block{ margin-bottom:22px; }
.gl-block-label{ font-family:var(--font-body); font-weight:700; font-size:12.5px; text-transform:uppercase; letter-spacing:.04em; color:var(--ink-faint); display:flex; align-items:center; gap:6px; margin-bottom:9px; }
.gl-block-label svg{ width:15px; height:15px; stroke:var(--accent); fill:none; stroke-width:2; }

/* formula chips */
.gl-formula-box{ background:linear-gradient(135deg, rgba(110,91,214,.08), rgba(30,154,144,.06)); border:1.5px dashed var(--accent); border-radius:var(--radius-md); padding:16px; display:flex; flex-wrap:wrap; gap:8px; align-items:center; }
.gl-chip{ font-family:'Courier New',monospace; font-weight:700; font-size:13.5px; background:var(--surface); border:1px solid var(--border); color:var(--ink); padding:6px 12px; border-radius:8px; }
.gl-chip-plus{ color:var(--ink-faint); font-weight:700; }

.gl-rule-text, .gl-why-text{ font-size:14.5px; line-height:1.65; color:var(--ink); background:var(--surface-2); padding:14px 16px; border-radius:var(--radius-sm); border-left:3px solid var(--accent); }
.gl-why-text{ border-left-color:var(--accent-3); }

.gl-tensegrid{ width:100%; border-collapse:collapse; font-size:13px; margin-top:6px; }
.gl-tensegrid th, .gl-tensegrid td{ text-align:left; padding:7px 10px; border-bottom:1px solid var(--border); }
.gl-tensegrid th{ color:var(--ink-faint); font-weight:700; font-size:11.5px; text-transform:uppercase; }
.gl-tensegrid td:nth-child(2){ font-family:'Courier New',monospace; color:var(--accent); }

.gl-level-tabs{ display:flex; gap:6px; margin-bottom:10px; }
.gl-level-btn{ font-size:12px; font-weight:700; padding:5px 12px; border-radius:99px; border:1px solid var(--border); background:var(--surface-2); color:var(--ink-soft); cursor:pointer; }
.gl-level-btn.is-active{ background:var(--accent-3); color:#fff; border-color:var(--accent-3); }
.gl-example-list{ list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:8px; }
.gl-example-list li{ font-size:14px; padding:9px 12px; background:var(--surface-2); border-radius:8px; }

.gl-mistake{ display:grid; grid-template-columns:1fr 1fr; gap:10px; padding:12px; background:var(--surface-2); border-radius:var(--radius-sm); margin-bottom:10px; }
.gl-mistake .wrong{ color:#C4432B; font-size:13.5px; }
.gl-mistake .right{ color:var(--success); font-size:13.5px; }
.gl-mistake .wrong::before{ content:'✗ '; font-weight:700; }
.gl-mistake .right::before{ content:'✓ '; font-weight:700; }
.gl-mistake .explain{ grid-column:1 / -1; font-size:12.8px; color:var(--ink-soft); border-top:1px dashed var(--border); padding-top:8px; margin-top:2px; }
@media(max-width:480px){ .gl-mistake{ grid-template-columns:1fr; } }

.gl-practice-card{ background:var(--surface-2); border-radius:var(--radius-sm); padding:14px; margin-bottom:10px; }
.gl-practice-q{ font-size:14px; font-weight:600; margin-bottom:10px; }
.gl-practice-opts{ display:flex; flex-direction:column; gap:7px; }
.gl-practice-opt{ text-align:left; font-size:13.5px; padding:9px 12px; border-radius:8px; border:1px solid var(--border); background:var(--surface); cursor:pointer; }
.gl-practice-opt:hover{ border-color:var(--accent); }
.gl-practice-opt.correct{ background:rgba(30,158,103,.12); border-color:var(--success); font-weight:600; }
.gl-practice-opt.wrong{ background:rgba(196,67,43,.1); border-color:#C4432B; }
.gl-practice-explain{ font-size:12.8px; color:var(--ink-soft); margin-top:9px; padding-top:9px; border-top:1px dashed var(--border); display:none; }
.gl-practice-explain.show{ display:block; }

.gl-prereq-row{ display:flex; flex-wrap:wrap; gap:7px; align-items:center; font-size:12.8px; color:var(--ink-soft); }
.gl-prereq-chip{ background:var(--surface-2); border:1px solid var(--border); padding:3px 10px; border-radius:99px; cursor:pointer; font-weight:600; color:var(--accent); }

.gl-actions{ display:flex; flex-wrap:wrap; gap:8px; margin-top:20px; padding-top:18px; border-top:1px solid var(--border); }
.gl-action-btn{ font-family:var(--font-body); font-weight:600; font-size:13px; padding:9px 15px; border-radius:99px; border:1px solid var(--border); background:var(--surface-2); color:var(--ink); cursor:pointer; display:flex; align-items:center; gap:6px; }
.gl-action-btn svg{ width:15px; height:15px; stroke:currentColor; fill:none; stroke-width:2; }
.gl-action-btn.primary{ background:var(--accent); color:var(--accent-ink); border-color:var(--accent); }
.gl-action-btn:hover{ border-color:var(--accent); }

/* ---------------------------------------------------------------------- */
/* TOOL PANELS (Analyzer / Mistake / Transform / Compare / Roadmap)        */
/* ---------------------------------------------------------------------- */
.gl-panel{ max-width:820px; margin:0 auto; background:var(--surface); border:1px solid var(--border); border-radius:var(--radius-lg); padding:26px; box-shadow:var(--shadow-sm); }
.gl-panel h3{ font-family:var(--font-display); font-size:20px; margin:0 0 6px; }
.gl-panel > p.gl-panel-sub{ color:var(--ink-soft); font-size:13.8px; margin:0 0 18px; }
.gl-textarea{ width:100%; min-height:88px; font-family:var(--font-body); font-size:14.5px; padding:13px 15px; border:1.5px solid var(--border); border-radius:var(--radius-sm); background:var(--bg); color:var(--ink); resize:vertical; }
.gl-textarea:focus{ outline:none; border-color:var(--accent); }
.gl-row{ display:flex; flex-wrap:wrap; gap:10px; align-items:center; margin-top:12px; }
.gl-select{ font-family:var(--font-body); font-size:13.5px; padding:9px 12px; border-radius:8px; border:1px solid var(--border); background:var(--surface); color:var(--ink); }
.gl-btn{ font-family:var(--font-body); font-weight:700; font-size:13.8px; padding:10px 20px; border-radius:99px; border:none; background:var(--accent); color:var(--accent-ink); cursor:pointer; }
.gl-btn:hover{ opacity:.92; }
.gl-btn.ghost{ background:var(--surface-2); color:var(--ink); border:1px solid var(--border); }

.gl-result{ margin-top:20px; }
.gl-token-line{ display:flex; flex-wrap:wrap; gap:6px; margin-bottom:16px; }
.gl-token{ position:relative; padding:6px 10px; border-radius:8px; font-size:14px; font-family:'Courier New',monospace; cursor:default; }
.gl-token small{ display:block; font-family:var(--font-body); font-size:9.5px; font-weight:700; text-transform:uppercase; margin-top:2px; opacity:.75; }
.gl-tag-subj{ background:rgba(110,91,214,.18); color:#4B3EAA; }
.gl-tag-aux{ background:rgba(30,154,144,.18); color:#0F6F67; }
.gl-tag-verb{ background:rgba(242,169,59,.22); color:#8A5B0A; }
.gl-tag-obj{ background:rgba(196,67,43,.14); color:#A2371F; }
.gl-tag-art{ background:rgba(150,150,170,.18); color:#565672; }
.gl-tag-prep{ background:rgba(95,207,195,.2); color:#0D746A; }
.gl-tag-conj{ background:rgba(255,110,150,.16); color:#B23B62; }
.gl-tag-pron{ background:rgba(110,91,214,.12); color:#5E4FC7; }
[data-theme="dark"] .gl-tag-subj{ color:#C8BEFF; }
[data-theme="dark"] .gl-tag-aux{ color:#7FE3D8; }
[data-theme="dark"] .gl-tag-verb{ color:#FFD98F; }
[data-theme="dark"] .gl-tag-obj{ color:#FFA98F; }
[data-theme="dark"] .gl-tag-prep{ color:#8FF0E3; }
[data-theme="dark"] .gl-tag-conj{ color:#FFA9C4; }
[data-theme="dark"] .gl-tag-pron{ color:#C8BEFF; }

.gl-facts{ display:grid; grid-template-columns:repeat(auto-fit,minmax(160px,1fr)); gap:10px; margin-bottom:14px; }
.gl-fact{ background:var(--surface-2); border-radius:var(--radius-sm); padding:12px 14px; }
.gl-fact-label{ font-size:11px; font-weight:700; text-transform:uppercase; color:var(--ink-faint); margin-bottom:3px; }
.gl-fact-val{ font-size:14.5px; font-weight:700; color:var(--accent); }
.gl-note{ font-size:12.8px; color:var(--ink-faint); margin-top:10px; line-height:1.55; }

.gl-detect-card{ background:var(--surface-2); border-radius:var(--radius-sm); padding:16px; }
.gl-detect-card .wrong, .gl-detect-card .right{ font-size:14.5px; }

.gl-compare-grid{ display:grid; grid-template-columns:1fr 1fr; gap:14px; margin-top:16px; }
@media(max-width:560px){ .gl-compare-grid{ grid-template-columns:1fr; } }
.gl-compare-col{ background:var(--surface-2); border-radius:var(--radius-md); padding:16px; }
.gl-compare-col h4{ font-family:var(--font-display); font-size:16px; margin:0 0 8px; color:var(--accent); }
.gl-compare-col .f{ font-family:'Courier New',monospace; font-size:13px; background:var(--surface); padding:8px 10px; border-radius:8px; margin-bottom:8px; }
.gl-compare-col .u{ font-size:13px; color:var(--ink-soft); margin-bottom:8px; }
.gl-compare-col .e{ font-size:13px; font-style:italic; }

.gl-roadmap{ display:flex; flex-direction:column; gap:16px; }
.gl-stage{ display:flex; flex-wrap:wrap; align-items:center; gap:10px; }
.gl-stage-label{ min-width:150px; font-weight:700; font-size:13px; color:var(--ink-soft); }
.gl-stage-topics{ display:flex; flex-wrap:wrap; gap:8px; flex:1; }
.gl-roadmap-chip{ font-size:12.8px; font-weight:600; padding:7px 13px; border-radius:99px; background:var(--surface-2); border:1px solid var(--border); cursor:pointer; }
.gl-roadmap-chip:hover{ border-color:var(--accent); color:var(--accent); }
.gl-roadmap-arrow{ color:var(--ink-faint); font-size:18px; }

.gl-practice-toolbar{ display:flex; flex-wrap:wrap; gap:10px; align-items:center; justify-content:space-between; margin-bottom:16px; }
.gl-score{ font-weight:700; font-size:13.5px; color:var(--accent); }

@media print{
  header.topbar, .gl-modes, .gl-search-wrap, .gl-catbar, .gl-actions, footer, .gl-modal-close{ display:none !important; }
  .gl-overlay{ position:static; background:none; backdrop-filter:none; padding:0; }
  .gl-modal{ box-shadow:none; border:none; max-width:100%; }
}